View source for One-time pad/Phix

<span style='font-size:220%;'>[[Phix]]</span><br>
A simple xor-based one time pad that allows any file to be encrypted and decrypted,
since it seems silly to limit this to plaintext.
The one time pad files are therefore binary rather than plain text, with comments
and used counts in separate .1te/.1td files, rather than #/- in the .1tp itself.
Uses a trivial xor rather than a Vigenere cipher, since the latter adds nothing.
Ignores the "true random numbers, eg from /dev/random" part, especially since the
wikipedia page cites /dev/random as potentially unsuitable for cryptographic use. 
Instead this just uses the builtin rand(): for better security I might suggest you
replace that, possibly with several different (pseudo) random number generators. 

The dump feature is only for testing, obviously, as is decrypt defaulting to the
last encrypted message/file/pad. Note however that .1te/.1td handling is not: if
you try to make a one time pad "bi-directional", then not only would there be some
confusion and re-alignment issues should both parties send a message at the same
time, but two messages encrypted with the same part of the one time pad severely
weakens the security of those two messages. To prevent that, delete/do not share
the .1te or .1td file, and it will not allow encryption/decryption respectively.

Note that options 4 (Encrypt plain text) and 5 (Decrypt cipher text) are also 
only suitable for testing: you cannot actually enter anything for option 5, it 
just decodes whatever was last encoded by option 4, however it would be trivial 
to store the output of option 4 in a file and send that, and the recipient would 
then decode it using option 7 (Decrypt file).

TIP: if a message gets lost, or you quit without decrypting something, then edit
the recipient's .1td file manually, so that Used matches the sender's .1te file.

<!--<syntaxhighlight lang="phix">(notonline)-->
 <span style="color: #004080;">string</span> <span style="color: #000000;">default_enc</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span><span style="color: #0000FF;">,</span>
        <span style="color: #000000;">default_dec</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span>
  
 <span style="color: #008080;">function</span> <span style="color: #000000;">size_used</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">name</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">now_used</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">object</span> <span style="color: #000000;">txt</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">read_lines</span><span style="color: #0000FF;">(</span><span style="color: #000000;">name</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #004080;">sequence</span><span style="color: #0000FF;">(</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">size</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">used</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
             <span style="color: #008080;">if</span> <span style="color: #7060A8;">match</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Size"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">])=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
                 <span style="color: #0000FF;">{{</span><span style="color: #000000;">size</span><span style="color: #0000FF;">}}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">scanf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span><span style="color: #008000;">"Size: %d"</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">elsif</span> <span style="color: #7060A8;">match</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Used"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">])=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
                 <span style="color: #008080;">if</span> <span style="color: #000000;">now_used</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                     <span style="color: #0000FF;">{{</span><span style="color: #000000;">used</span><span style="color: #0000FF;">}}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">scanf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span><span style="color: #008000;">"Used: %d"</span><span style="color: #0000FF;">)</span>
                     <span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">size</span><span style="color: #0000FF;">,</span><span style="color: #000000;">used</span><span style="color: #0000FF;">}</span>
                 <span style="color: #008080;">else</span>
                     <span style="color: #000000;">txt</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Used: %d"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">now_used</span><span style="color: #0000FF;">)</span>
                     <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">write_lines</span><span style="color: #0000FF;">(</span><span style="color: #000000;">name</span><span style="color: #0000FF;">,</span><span style="color: #000000;">txt</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
                         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error updating %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">name</span><span style="color: #0000FF;">})</span>
                     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
                     <span style="color: #008080;">return</span> <span style="color: #000000;">1</span>
                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">return</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">list_one_time_pads</span><span style="color: #0000FF;">(</span><span style="color: #004080;">bool</span> <span style="color: #000000;">set_default</span><span style="color: #0000FF;">=</span><span style="color: #004600;">false</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">sequence</span> <span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">dir</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"*.1t?"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">d</span><span style="color: #0000FF;">={}</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"No one time pad files found.\n"</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">return</span>
     <span style="color: #008080;">elsif</span> <span style="color: #000000;">set_default</span> <span style="color: #008080;">then</span>
         <span style="color: #004080;">sequence</span> <span style="color: #000000;">bases</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span>
                  <span style="color: #000000;">types</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{},{},{}}</span>     <span style="color: #000080;font-style:italic;">-- p/e/d</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
             <span style="color: #004080;">string</span> <span style="color: #000000;">name</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">d</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #004600;">D_NAME</span><span style="color: #0000FF;">]</span>
             <span style="color: #004080;">integer</span> <span style="color: #000000;">dot</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">name</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">if</span> <span style="color: #000000;">dot</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                 <span style="color: #004080;">string</span> <span style="color: #000000;">base</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">name</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">dot</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">],</span>
                        <span style="color: #000000;">ext</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">name</span><span style="color: #0000FF;">[</span><span style="color: #000000;">dot</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..$]</span>
                 <span style="color: #004080;">integer</span> <span style="color: #000000;">e</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ext</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"1tp"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"1te"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"1td"</span><span style="color: #0000FF;">})</span>
                 <span style="color: #008080;">if</span> <span style="color: #000000;">e</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                     <span style="color: #004080;">integer</span> <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">base</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bases</span><span style="color: #0000FF;">)</span>
                     <span style="color: #008080;">if</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                         <span style="color: #000000;">bases</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">bases</span><span style="color: #0000FF;">,</span><span style="color: #000000;">base</span><span style="color: #0000FF;">)</span>
                         <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">bases</span><span style="color: #0000FF;">)</span>
                     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
                     <span style="color: #000000;">types</span><span style="color: #0000FF;">[</span><span style="color: #000000;">e</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">k</span>
                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
         <span style="color: #000000;">default_enc</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">types</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])=</span><span style="color: #000000;">1</span><span style="color: #0000FF;">?</span><span style="color: #000000;">bases</span><span style="color: #0000FF;">[</span><span style="color: #000000;">types</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]]&</span><span style="color: #008000;">".1te"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">""</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">default_dec</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">types</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])=</span><span style="color: #000000;">1</span><span style="color: #0000FF;">?</span><span style="color: #000000;">bases</span><span style="color: #0000FF;">[</span><span style="color: #000000;">types</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]]&</span><span style="color: #008000;">".1td"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">""</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">else</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
             <span style="color: #004080;">sequence</span> <span style="color: #000000;">di</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">d</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
             <span style="color: #004080;">string</span> <span style="color: #000000;">name</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">di</span><span style="color: #0000FF;">[</span><span style="color: #004600;">D_NAME</span><span style="color: #0000FF;">],</span>
                    <span style="color: #000000;">info</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">name</span><span style="color: #0000FF;">[$]=</span><span style="color: #008000;">'p'</span><span style="color: #0000FF;">?</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Size: %d"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">di</span><span style="color: #0000FF;">[</span><span style="color: #004600;">D_SIZE</span><span style="color: #0000FF;">])</span>
                          <span style="color: #0000FF;">:</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Size: %d, Used: %d"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">size_used</span><span style="color: #0000FF;">(</span><span style="color: #000000;">name</span><span style="color: #0000FF;">)))</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s  Created: %02d/%02d/%04d, %s\n"</span><span style="color: #0000FF;">,</span>
                      <span style="color: #0000FF;">{</span><span style="color: #000000;">name</span><span style="color: #0000FF;">,</span><span style="color: #000000;">di</span><span style="color: #0000FF;">[</span><span style="color: #004600;">D_DAY</span><span style="color: #0000FF;">],</span><span style="color: #000000;">di</span><span style="color: #0000FF;">[</span><span style="color: #004600;">D_MONTH</span><span style="color: #0000FF;">],</span><span style="color: #000000;">di</span><span style="color: #0000FF;">[</span><span style="color: #004600;">D_YEAR</span><span style="color: #0000FF;">],</span><span style="color: #000000;">info</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">dump_hex</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"{}\n"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">else</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%02x%c"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">mod</span><span style="color: #0000FF;">(</span><span style="color: #000000;">i</span><span style="color: #0000FF;">,</span><span style="color: #000000;">16</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">?</span><span style="color: #008000;">'\n'</span><span style="color: #0000FF;">:</span><span style="color: #008000;">' '</span><span style="color: #0000FF;">)})</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #004080;">string</span> <span style="color: #000000;">file</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">bool</span> <span style="color: #000000;">ashex</span><span style="color: #0000FF;">=</span><span style="color: #004600;">false</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"The contents of %s:\n\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">file</span><span style="color: #0000FF;">})</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">match</span><span style="color: #0000FF;">(</span><span style="color: #008000;">".1tp"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">file</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">or</span> <span style="color: #000000;">ashex</span> <span style="color: #008080;">then</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">file</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"rb"</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">dump_hex</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">get_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">64</span><span style="color: #0000FF;">))</span>
         <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
         <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">get_file_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">file</span><span style="color: #0000FF;">)></span><span style="color: #000000;">64</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"...\n\n"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">))</span>
     <span style="color: #008080;">else</span>
         <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">read_lines</span><span style="color: #0000FF;">(</span><span style="color: #000000;">file</span><span style="color: #0000FF;">),</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)&</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">create_one_time_pad</span><span style="color: #0000FF;">()</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">filename</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"OTP file name to create (without extension):"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"extension not allowed\n"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">elsif</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">!=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span>
         <span style="color: #004080;">string</span> <span style="color: #000000;">pfile</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">&</span><span style="color: #008000;">".1tp"</span><span style="color: #0000FF;">,</span>
                <span style="color: #000000;">efile</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">&</span><span style="color: #008000;">".1te"</span><span style="color: #0000FF;">,</span>
                <span style="color: #000000;">dfile</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">&</span><span style="color: #008000;">".1td"</span>
         <span style="color: #008080;">if</span> <span style="color: #7060A8;">file_exists</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
             <span style="color: #004080;">string</span> <span style="color: #000000;">del</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">lower</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"File already exists - delete?:"</span><span style="color: #0000FF;">))</span>
             <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">del</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"y"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"yes"</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">delete_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
                 <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error deleting %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">})</span>
                 <span style="color: #008080;">return</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #004080;">string</span> <span style="color: #000000;">comment</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"comment (optional):"</span><span style="color: #0000FF;">)</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">filesize</span>
         <span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
             <span style="color: #004080;">string</span> <span style="color: #000000;">sizestr</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"file size (1MB):"</span><span style="color: #0000FF;">)</span>
             <span style="color: #004080;">sequence</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sizestr</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span><span style="color: #0000FF;">?{{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"MB"</span><span style="color: #0000FF;">}}:</span><span style="color: #7060A8;">scanf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sizestr</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%d%s"</span><span style="color: #0000FF;">))</span>
             <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
                 <span style="color: #004080;">integer</span> <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]),{</span><span style="color: #008000;">""</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"K"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"KB"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"M"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"MB"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"G"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"GB"</span><span style="color: #0000FF;">})</span>
                 <span style="color: #008080;">if</span> <span style="color: #000000;">k</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                     <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1024</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1024</span><span style="color: #0000FF;">*</span><span style="color: #000000;">1024</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1024</span><span style="color: #0000FF;">*</span><span style="color: #000000;">1204</span><span style="color: #0000FF;">}[</span><span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">k</span><span style="color: #0000FF;">/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
                     <span style="color: #000000;">filesize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">res</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]*</span><span style="color: #000000;">k</span>
                     <span style="color: #008080;">exit</span>
                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
                 <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"unknown suffix:%s - use K|M|G or KB|MB|GB\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">res</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]})</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Creating %s (%d bytes)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">})</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"wb"</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error opening %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">})</span>
             <span style="color: #008080;">return</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">filesize</span> <span style="color: #008080;">do</span>
             <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">rand</span><span style="color: #0000FF;">(</span><span style="color: #000000;">256</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
         <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"w"</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error opening %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">})</span>
             <span style="color: #008080;">return</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"# OTP file\n# %s\nSize: %d\nUsed: 0\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">comment</span><span style="color: #0000FF;">,</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">})</span>
         <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">copy_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dfile</span><span style="color: #0000FF;">,</span><span style="color: #004600;">true</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error copying %s to %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dfile</span><span style="color: #0000FF;">})</span>
             <span style="color: #008080;">return</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n%s and %s and %s have been created in the current directory.\n\n"</span><span style="color: #0000FF;">,</span>
                  <span style="color: #0000FF;">{</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dfile</span><span style="color: #0000FF;">})</span>
         <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pfile</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">default_enc</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">efile</span>
         <span style="color: #000000;">default_dec</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">dfile</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">delete_one_time_pad</span><span style="color: #0000FF;">()</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">filename</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"OTP file name to delete (without extension):"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"extension not allowed\n"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">elsif</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">!=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span>
         <span style="color: #004080;">string</span> <span style="color: #000000;">efile</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">&</span><span style="color: #008000;">".1te"</span><span style="color: #0000FF;">,</span>
                <span style="color: #000000;">dfile</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">&</span><span style="color: #008000;">".1td"</span>
         <span style="color: #000000;">filename</span> <span style="color: #0000FF;">&=</span> <span style="color: #008000;">".1tp"</span>
         <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">file_exists</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"file %s found\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">})</span>
             <span style="color: #008080;">return</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #004080;">string</span> <span style="color: #000000;">del</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">lower</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Delete file - are you sure?:"</span><span style="color: #0000FF;">))</span>
         <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">del</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"y"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"yes"</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"file not deleted\n"</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">return</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">delete_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error deleting %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">})</span>
             <span style="color: #008080;">return</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">c</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
         <span style="color: #000000;">c</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">delete_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span>
         <span style="color: #000000;">c</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">delete_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dfile</span><span style="color: #0000FF;">)</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%d file%s successfully deleted.\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">c</span><span style="color: #0000FF;">,</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span><span style="color: #0000FF;">?</span><span style="color: #008000;">""</span><span style="color: #0000FF;">:</span><span style="color: #008000;">"s"</span><span style="color: #0000FF;">)})</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">default_enc</span><span style="color: #0000FF;">=</span><span style="color: #000000;">efile</span> <span style="color: #008080;">then</span> <span style="color: #000000;">default_enc</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">default_dec</span><span style="color: #0000FF;">=</span><span style="color: #000000;">dfile</span> <span style="color: #008080;">then</span> <span style="color: #000000;">default_dec</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #004080;">sequence</span> <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">crypt_text</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">de</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">sequence</span> <span style="color: #000000;">text</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'d'</span><span style="color: #0000FF;">?</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">:</span><span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"message:"</span><span style="color: #0000FF;">))</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">dflt</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'d'</span><span style="color: #0000FF;">?</span><span style="color: #000000;">default_dec</span><span style="color: #0000FF;">:</span><span style="color: #000000;">default_enc</span><span style="color: #0000FF;">),</span>
            <span style="color: #000000;">otp</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dflt</span><span style="color: #0000FF;">)?</span><span style="color: #008000;">"OTP ("</span><span style="color: #0000FF;">&</span><span style="color: #000000;">dflt</span><span style="color: #0000FF;">&</span><span style="color: #008000;">"):"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">"OTP:"</span><span style="color: #0000FF;">),</span>
            <span style="color: #000000;">efile</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #000000;">otp</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">efile</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span> <span style="color: #000000;">efile</span><span style="color: #0000FF;">=</span><span style="color: #000000;">dflt</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
         <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #000000;">efile</span> <span style="color: #0000FF;">&=</span> <span style="color: #008000;">".1t"</span><span style="color: #0000FF;">&</span><span style="color: #000000;">de</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">size</span><span style="color: #0000FF;">,</span><span style="color: #000000;">used</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">size_used</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">size</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">or</span> <span style="color: #000000;">used</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"File %s cannot be opened\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">elsif</span> <span style="color: #000000;">used</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">)></span><span style="color: #000000;">size</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"OTP exhausted (%d&gt;%d)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">used</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">),</span><span style="color: #000000;">size</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">else</span>
             <span style="color: #000000;">efile</span><span style="color: #0000FF;">[$]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'p'</span>
             <span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"rb"</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">if</span> <span style="color: #7060A8;">seek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">used</span><span style="color: #0000FF;">)!=</span><span style="color: #004600;">SEEK_OK</span> <span style="color: #008080;">then</span>
                 <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Error in seek(%s,%d)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">})</span>
                 <span style="color: #000000;">text</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span>
             <span style="color: #008080;">else</span>    
                 <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">get_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">))</span>
                 <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sq_xor_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">,</span><span style="color: #000000;">text</span><span style="color: #0000FF;">)</span>
                 <span style="color: #008080;">if</span> <span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'e'</span> <span style="color: #008080;">then</span>
                     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Encrypted:\n"</span><span style="color: #0000FF;">)</span>
                     <span style="color: #000000;">dump_hex</span><span style="color: #0000FF;">(</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">)</span>
                     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n\n"</span><span style="color: #0000FF;">)</span>
                 <span style="color: #008080;">else</span>
                     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Decrypted: %s\n\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">})</span>
                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
             <span style="color: #000000;">efile</span><span style="color: #0000FF;">[$]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">de</span>
             <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">)!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                 <span style="color: #0000FF;">{}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">size_used</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">used</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">text</span><span style="color: #0000FF;">))</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #004080;">string</span> <span style="color: #000000;">last_file</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span>
  
 <span style="color: #008080;">procedure</span> <span style="color: #000000;">crypt_file</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">de</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">file</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'d'</span> <span style="color: #008080;">and</span> <span style="color: #000000;">last_file</span><span style="color: #0000FF;">!=</span><span style="color: #008000;">""</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"file ("</span><span style="color: #0000FF;">&</span><span style="color: #000000;">last_file</span><span style="color: #0000FF;">&</span><span style="color: #008000;">"):"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">"file:"</span><span style="color: #0000FF;">),</span>
            <span style="color: #000000;">filename</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #000000;">file</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'d'</span> <span style="color: #008080;">and</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">=</span><span style="color: #000000;">last_file</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">filename</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">file_exists</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"The file %s does not exist\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">return</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #004080;">atom</span> <span style="color: #000000;">filesize</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">get_file_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"rb"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">fn</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error opening %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">return</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #004080;">sequence</span> <span style="color: #000000;">bytes</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">get_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">bytes</span><span style="color: #0000FF;">)!=</span><span style="color: #000000;">filesize</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- uh?</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'e'</span> <span style="color: #008080;">then</span>
         <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">filename</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">true</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">outfile</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"output:"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">outfile</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #004080;">integer</span> <span style="color: #000000;">outfn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">outfile</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"wb"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">outfn</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
         <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"error opening output file %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">outfile</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">return</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">dflt</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'d'</span><span style="color: #0000FF;">?</span><span style="color: #000000;">default_dec</span><span style="color: #0000FF;">:</span><span style="color: #000000;">default_enc</span><span style="color: #0000FF;">),</span>
            <span style="color: #000000;">otp</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dflt</span><span style="color: #0000FF;">)?</span><span style="color: #008000;">"OTP ("</span><span style="color: #0000FF;">&</span><span style="color: #000000;">dflt</span><span style="color: #0000FF;">&</span><span style="color: #008000;">"):"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">"OTP:"</span><span style="color: #0000FF;">),</span>
            <span style="color: #000000;">efile</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_string</span><span style="color: #0000FF;">(</span><span style="color: #000000;">otp</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">efile</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span> <span style="color: #000000;">efile</span><span style="color: #0000FF;">=</span><span style="color: #000000;">dflt</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
         <span style="color: #008080;">if</span> <span style="color: #008080;">not</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'.'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #000000;">efile</span> <span style="color: #0000FF;">&=</span> <span style="color: #008000;">".1t"</span><span style="color: #0000FF;">&</span><span style="color: #000000;">de</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
         <span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">size</span><span style="color: #0000FF;">,</span><span style="color: #000000;">used</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">size_used</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">if</span> <span style="color: #000000;">size</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">or</span> <span style="color: #000000;">used</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"File %s cannot be opened\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">elsif</span> <span style="color: #000000;">used</span><span style="color: #0000FF;">+</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">></span><span style="color: #000000;">size</span> <span style="color: #008080;">then</span>
             <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"OTP exhausted (%d&gt;%d)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">used</span><span style="color: #0000FF;">+</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">,</span><span style="color: #000000;">size</span><span style="color: #0000FF;">})</span>
         <span style="color: #008080;">else</span>
             <span style="color: #000000;">efile</span><span style="color: #0000FF;">[$]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'p'</span>
             <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"rb"</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">if</span> <span style="color: #7060A8;">seek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">used</span><span style="color: #0000FF;">)!=</span><span style="color: #004600;">SEEK_OK</span> <span style="color: #008080;">then</span>
                 <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Error in seek(%s,%d)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">})</span>
                 <span style="color: #000000;">filesize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
             <span style="color: #008080;">else</span>    
                 <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">get_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">)</span>
                 <span style="color: #000000;">msg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sq_xor_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bytes</span><span style="color: #0000FF;">)</span>
                 <span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">outfn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">msg</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
             <span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">outfn</span><span style="color: #0000FF;">)</span>
             <span style="color: #000000;">efile</span><span style="color: #0000FF;">[$]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">de</span>
             <span style="color: #008080;">if</span> <span style="color: #000000;">filesize</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
                 <span style="color: #0000FF;">{}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">size_used</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">used</span><span style="color: #0000FF;">+</span><span style="color: #000000;">filesize</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #008080;">if</span> <span style="color: #000000;">de</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'d'</span> <span style="color: #008080;">then</span>
                 <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">outfile</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">true</span><span style="color: #0000FF;">)</span>
             <span style="color: #008080;">else</span>
                 <span style="color: #000000;">last_file</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">outfile</span>
             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
             <span style="color: #000000;">dump_file</span><span style="color: #0000FF;">(</span><span style="color: #000000;">efile</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
  
 <span style="color: #000000;">list_one_time_pads</span><span style="color: #0000FF;">(</span><span style="color: #000000;">set_default</span><span style="color: #0000FF;">:=</span><span style="color: #004600;">true</span><span style="color: #0000FF;">)</span>
  
 <span style="color: #000080;font-style:italic;">-- note: the trailing space after the opening """ is deliberate:</span>
 <span style="color: #008080;">constant</span> <span style="color: #000000;">menu_txt</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""" 
 1. List one time pad files.
 2. Create one time pad file.
 3. Delete one time pad file.
 4. Encrypt plain text.
 5. Decrypt cipher text.
 6. Encrypt file.
 7. Decrypt file.
 8. Quit program.
 Your choice (1 to 8) : """</span>
  
 <span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
     <span style="color: #004080;">integer</span> <span style="color: #000000;">choice</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">prompt_number</span><span style="color: #0000FF;">(</span><span style="color: #000000;">menu_txt</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">8</span><span style="color: #0000FF;">})</span>
     <span style="color: #008080;">switch</span> <span style="color: #000000;">choice</span> <span style="color: #008080;">do</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">list_one_time_pads</span><span style="color: #0000FF;">()</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">create_one_time_pad</span><span style="color: #0000FF;">()</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">3</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">delete_one_time_pad</span><span style="color: #0000FF;">()</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">4</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">crypt_text</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'e'</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">5</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">crypt_text</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'d'</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">6</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">crypt_file</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'e'</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">7</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">crypt_file</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'d'</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">case</span> <span style="color: #000000;">8</span><span style="color: #0000FF;">:</span> <span style="color: #008080;">exit</span>
         <span style="color: #008080;">default</span> <span style="color: #0000FF;">:</span><span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"not implemented...\n"</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<!--</syntaxhighlight>-->

{{out}}
Sample session. Similar to Kotlin, menu display/selection has been shorted to <menu N. Xxxx.><br>
<pre>
No one time pad files found.

1. List one time pad files.
2. Create one time pad file.
3. Delete one time pad file.
4. Encrypt plain text.
5. Decrypt cipher text.
6. Encrypt file.
7. Decrypt file.
8. Quit program.
Your choice (1 to 8) : 2
OTP file name to create (without extension):007
comment (optional):Pussy Galore
file size (1MB):
Creating 007.1tp (1048576 bytes)

007.1tp and 007.1te and 007.1td have been created in the current directory.

The contents of 007.1tp:

C3 A1 90 B2 70 E6 A2 DD 27 F4 3C 21 48 D1 54 1C
D7 7E AA 09 40 CC 49 83 F4 E3 96 86 1D 48 15 F6
A3 C2 5F 47 00 BE D1 6B 4E 4A EA 50 DB F8 62 2F
D5 66 D5 0F A9 63 E6 4D 65 BB 67 70 6F 51 34 73
...

The contents of 007.1te:

# OTP file
# Pussy Galore
Size: 1048576
Used: 0

<menu 1. List one time pad files.>
007.1td  Created: 10/11/2018, Size: 1048576, Used: 0
007.1te  Created: 10/11/2018, Size: 1048576, Used: 0
007.1tp  Created: 10/11/2018, Size: 1048576

<menu 4. Encrypt plain text.>
message:This is message 1234
OTP (007.1te):
Encrypted:
97 C9 F9 C1 50 8F D1 FD 4A 91 4F 52 29 B6 31 3C
E6 4C 99 3D

The contents of 007.1te:

# OTP file
# Pussy Galore
Size: 1048576
Used: 20

<menu 5. Decrypt cipher text.>
OTP (007.1td):
Decrypted: This is message 1234

The contents of 007.1td:

# OTP file
# Pussy Galore
Size: 1048576
Used: 20

<menu 8. Quit program.>
</pre>